Both electrical and chemical synapses mediate fast network oscillations in the olfactory bulb
Both electrical and chemical synapses mediate fast network oscillations in the olfactory bulb
复制标题
DOI：
10.1152/jn.00887.2002
复制
发表时间：
2003-05-01
影响因子：
2.5
通讯作者：
Strowbridge, BW
中科院分区：
文献类型：
--
作者：
Friedman, D;Strowbridge, BW
气味感知依赖于嗅觉脑区的分子、细胞和网络相互作用。近年来，人们对一级嗅觉区嗅觉上皮神经元的气味反应的细胞和分子机制有了更好的了解。在高阶感觉区域，神经元网络的同步活动被认为是气味处理的一个突出特征。对气味的感知和辨别与快速（20-70赫兹）脑电图振荡有关。这些快速网络振荡背后的细胞机制尚未被定义。在这项研究中，我们表明，在体外，短暂的电刺激可以在大鼠嗅球中引起同步快速振荡，部分模仿该大脑区域对感觉输入的自然反应。刺激诱导二尖瓣细胞的周期性抑制性突触电位和gaba能颗粒细胞的延长尖峰。反复刺激导致颗粒细胞活性和二尖瓣细胞抑制的持续增强。现场记录中突出的振荡表明刺激诱发了嗅球神经元网络的高频活动。由于谷氨酸受体拮抗剂和间隙连接抑制剂阻断振荡的细胞内和场反应，网络同步是化学和电突触相互作用的结果。我们的研究结果表明，嗅球可以通过抑制中间神经元网络的持续激活自主产生快速振荡。这些局部电路的相互作用可能在体内的气味处理中起关键作用。
Odor perception depends on a constellation of molecular, cellular, and network interactions in olfactory brain areas. Recently, there has been better understanding of the cellular and molecular mechanisms underlying the odor responses of neurons in the olfactory epithelium, the first-order olfactory area. In higher order sensory areas, synchronized activity in networks of neurons is known to be a prominent feature of odor processing. The perception and discrimination of odorants is associated with fast (20-70 Hz) electroencephalographic oscillations. The cellular mechanisms underlying these fast network oscillations have not been defined. In this study, we show that synchronous fast oscillations can be evoked by brief electrical stimulation in the rat olfactory bulb in vitro, partially mimicking the natural response of this brain region to sensory input. Stimulation induces periodic inhibitory synaptic potentials in mitral cells and prolonged spiking in GABAergic granule cells. Repeated stimulation leads to the persistent enhancement in both granule cell activity and mitral cell inhibition. Prominent oscillations in field recordings indicate that stimulation induces high-frequency activity throughout networks of olfactory bulb neurons. Network synchronization results from chemical and electrical synaptic interactions since both glutamate-receptor antagonists and gap junction inhibitors block oscillatory intracellular and field responses. Our results demonstrate that the olfactory bulb can generate fast oscillations autonomously through the persistent activation of networks of inhibitory interneurons. These local circuit interactions may be critically involved in odor processing in vivo.